Diacetyl, also known as 2,3-butanedione, and the closely related chemical 2,3-pentanedione, are naturally occurring substances with a characteristic butter-like odour found in foods such as dairy products, beer and fruits. Diacetyl is also added to various food products as artificial butter flavouring and both substances are present in emissions generated by coffee roasting and grinding. Occupational levels of diacetyl exposure has been linked with the lung disease bronchiolitis obliterans which is life threatening and irreversible. In Great Britain, occupational exposure limits to protect workers'...

Diacetyl and its substitute, 2,3-pentanedione, are widely used as flavoring compounds. The National Institute for Occupational Safety and Health (NIOSH) objective in establishing recommended exposure limits (RELs) for diacetyl and 2,3-pentanedione is to reduce the risk of respiratory impairment (decreased lung function) and the severe irreversible lung disease obliterative bronchiolitis associated with occupational exposure. In this Criteria Document, NIOSH reviews the scientific literature concerning potential health effects, toxicology, and risk assessment pertaining to diacetyl and 2,3-pentanedione...

Rationale: Obliterative bronchiolitis in former coffee workers prompted a cross-sectional study of current workers. Diacetyl and 2,3-pentanedione levels were highest in areas for flavoring and grinding/packaging unflavored coffee. Methods: We interviewed 75 (88%) workers, measured lung function, and created exposure groups based on work history. We calculated standardized morbidity ratios (SMRs) for symptoms and spirometric abnormalities. We examined health outcomes by exposure groups. Results: SMRs were elevated 1.6-fold for dyspnea and 2.7-fold for obstruction. The exposure group working in both...

Workers who handle diacetyl or work in areas where diacetyl exposure occurs are at risk of developing severe lung disease if their exposures are not properly controlled. The National Institute for Occupational Safety and Health (NIOSH) has developed guidance in a variety of areas to reduce workers' exposures to diacetyl through engineering controls, best work practices, and techniques for monitoring airborne diacetyl exposures. Although these guidelines emphasize diacetyl, they can be applied to reduce exposures to diacetyl substitutes such as 2,3-pentanedione and other alpha-diketones. Source...

Diacetyl is imported predominantly for use in formulations in the food flavouring industry. There have been reports, mainly in the USA, of damage to the respiratory system caused by inhalation. This report presents the findings of a small study to investigate exposures to diacetyl amongst workers employed in the food flavouring and fragrance industries. The report also includes from previous HSE/HSL visits. Exposures to diacetyl are generally of short duration, nonetheless, there is potential for workers to be exposed to airborne levels above those recommended by the EU Scientific Committee on...

Objectives: To better understand respiratory symptoms and lung function in flavouring manufacturing workers. Methods: We offered a questionnaire and lung function testing to the current workforce of a flavouring manufacturing facility that had transitioned away from diacetyl and towards substitutes in recent years. We examined symptoms, spirometric parameters and diffusing capacity measurements by exposure variables, including facility tenure and time spent daily in production areas. We used linear and logistic regression to develop final models adjusted for age and smoking status. Results: A total...

Commercial flavorings used in the food service industry are often complex mixtures of flavoring chemicals, many of which are volatile, meaning that they evaporate into the air from their liquid or solid form. Diacetyl is a prominent chemical ingredient in butter flavorings and is a component of the vapors coming from these and other flavorings. Inhalation of butter flavoring chemical mixtures, including diacetyl, has been associated with severe obstructive lung disease popularly know as "popcorn lung." In many symptomatic individuals exposed to flavoring who have undergone lung biopsy...